Alkaloids, Kratom Guides

Mitragynine: Getting to Know This Powerful Alkaloid

Kratom is a Southeast Asian herb used in traditional medicine to treat a host of conditions, including chronic pain, anxiety, and insomnia.

While many parts of this plant contribute to its greatness, mitragynine — a chemical naturally found within kratom leaves — is the real hero.

This article covers all you need to know about mitragynine, the compound in kratom responsible for many of its therapeutic properties.

Last updated 3 days ago by Wade Paul

Mitragynine: Getting to Know This Powerful Alkaloid

What Is Mitragynine?

Mitragynine is a psychoactive alkaloid found in the Southeast Asian plant Mitragyna speciosa (kratom).

Alkaloids are a broad family of organic compounds that must contain at least one nitrogen atom. They can have many different uses, and the specific effects of each alkaloid depend on the particular chemical structure. Caffeine and nicotine are two alkaloids most people are familiar with.

Kratom contains other alkaloids in addition to mitragynine, most notably 7-hydroxymitragynine. However, mitragynine is the most prevalent alkaloid in most kratom strains and is responsible for much of kratom’s energizing properties and some pain relief.

Where Does Mitragynine Come From?

Four Mitragyna species have mitragynine: M. speciosa, M. hirsuta, M. javanica, and M. rotdifolia.

Mitragyna speciosa contains the most; the others only have a small amount. Mitragynine isn’t the only alkaloid produced by kratom plants, but it is the most abundant alkaloid by a considerable margin.

Most kratom strains contain between 0.5 and 1.5% alkaloid concentrations, most of which is mitragynine. Different kratom strains contain varying amounts of mitragynine, depending on where they’re grown and how farmers cultivate them.

Other primary kratom alkaloids include: 

  1. 7-hydroxymitragynine
  2. Corynantheidine
  3. Paynantheine
  4. Speciocilliatine
  5. Speciogynine

Which Kratom Strains Are Highest in Mitragynine?

Although all kratom strains contain some mitragynine, white kratom strains tend to have more mitragynine than green or red kratom.

Thai strains also tend to have higher mitragynine concentrations, comprising up to 66% of the total alkaloid content. By contrast, Malaysian strains only contain about 12%.

If you’re looking for a kratom strain with large amounts of mitragynine, White Thai or White Malay will likely suit you best. Other strains high in mitragynine include White and Red Borneo and Red, White, and Green Maeng Da.

What Does Mitragynine Do?

Mitragynine has several interesting physiological effects that make it a popular herbal treatment for many conditions.

1. Pain Relief

Mitragynine’s most attractive quality for many people is that it acts as an analgesic. Mitragynine can ease pain by blocking pain signals before they reach the brain in higher amounts. It also shows alpha-2 adrenergic agonist activity [1].

While it’s less effective than 7-hydroxymitragynine, it’s still a potent pain reliever. Mitragynine can also help people relax by relieving muscle tension, further reducing pain in some cases.

2. Relaxant

Since mitragynine has calming effects in larger doses, it’s a great sleep aid and anxiety management tool [2]. Many kratom users report having a better handle on their anxiety when taking it, a benefit they can thank mitragynine for.

3. Increase Energy

Mitragynine’s effects are quite different in small doses. Taking small amounts of mitragynine can energize and enhance motivation and improve mood [3].

Some people claim that mitragynine also has mild nootropic properties, aiding in focus and enhancing general cognitive performance.

Mitragynine shows psychostimulant effects along with its opioid-like activity [4].

It is important to note that mitragynine is not the only alkaloid in kratom. Mitragynine plays a key role in generating kratom’s effects, but it doesn’t act alone. Other alkaloids working alongside mitragynine ultimately create the impact.

Is Mitragynine an Opiate?

Mitragynine is often compared to opiates since it has similar effects, but mitragynine is not an opiate. The pain-relieving aspect of mitragynine makes it a popular treatment for opiate withdrawal, easing the painful withdrawal symptoms and making it easier to avoid relapses.

It does interact with opioid receptors in your body, but it doesn’t cause respiratory depression, the leading cause of death in opioid overdose [5].

Suggested Reading: Is Kratom Dangerous?

Is Mitragynine Safe?

Like many natural remedies, mitragynine is generally safe if used responsibly [6]. The most significant risk faced by mitragynine users is addiction, drug interactions, or kratom that’s contaminated — all of which are avoidable.

By limiting weekly intake and taking regular breaks from kratom, you’ll prevent developing dependence.

Suggested Reading: Can You Overdose on Kratom?

Side Effects of Mitragynine

Mitragynine can have unintended side effects, especially when larger amounts of kratom are taken. The most common side effects are nausea, vertigo, and mental fogginess. Experts suggest keeping your dose small if you’re concerned about experiencing unwanted side effects.

How Much Mitragynine Should I Take?

It is rare for someone to take mitragynine on its own; most people take it as kratom.

The right dose for a given person depends on their metabolism, the kratom strain they’re taking, and the effects they desire.

Most people recommend beginners stick to small doses of between 1 and 3 grams. In small amounts, kratom is stimulating and will induce a mild high. Low doses also mean the effects are less intense and last for shorter durations.

More experienced users and people looking for a relaxing experience can up the dose to 3-6 grams. In this range, kratom produces a noticeable soothing effect and offers significant pain relief.

For even more pain relief and an intensely calming effect, users can take somewhere around 8 to 10 grams. This dose range can be too intense for some people, and it is more common for people to experience side effects when taking more significant amounts.

If you’re unsure, a kratom dose calculator can help you get an approximate amount based on your weight and desired effects.

How Long Do the Effects of Mitragynine Last?

How long the effects of mitragynine last depends on how much you take. Low kratom doses in the 2 to 5-gram range typically have effects that last for 1-2 hours. Effects from larger doses between 5 and 10 grams last longer, often upwards of 3-4 hours.

Mitragynine has a biological half-life in the human body of around three and a half hours [7]. This means that significant amounts of mitragynine remain in your system for the first few hours after consumption.

However, there typically won’t be any noticeable psychoactive effects after an hour or two at smaller doses, even though mitragynine is still present in your body.

Wrapping Up: Final Thoughts on Mitragynine

Mitragynine is the predominant alkaloid in kratom, giving it many of its psychoactive properties. It is a mild analgesic, can induce euphoria in small amounts, and aids sleep and relaxation at higher doses.

Most people take mitragynine by taking kratom; it’s important to remember that kratom contains other alkaloids that create the overall experience.

Mitragynine’s effects typically last for a few hours, with larger doses leading to results that last longer. Even after the perceptible effects subside, mitragynine remains present in the human body for almost a week.


  1. Vicknasingam, B., Chooi, W. T., Rahim, A. A., Ramachandram, D., Singh, D., Ramanathan, S., … & Chawarski, M. C. (2020). Focus: Plant-based Medicine and Pharmacology: Kratom and Pain Tolerance: A Randomized, Placebo-Controlled, Double-Blind Study. The Yale Journal of Biology and Medicine, 93(2), 229.
  2. Suhaimi, F. W., Yusoff, N. H., Hassan, R., Mansor, S. M., Navaratnam, V., Müller, C. P., & Hassan, Z. (2016). Neurobiology of Kratom and its main alkaloid mitragynine. Brain research bulletin, 126, 29-40.
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